ROS通过X连锁KDM6A调控IVF胚胎X染色体失活在子代小鼠肿瘤发生中的作用及机制研究

体外受精IVF技术增加子代肿瘤发生风险，但机制不清。我们前期研究发现IVF过程中氧化应激诱导胚胎X染色体非整倍体形成，提示可能发生异常的X染色体失活XCI。预实验证实氧化应激导致异常的XCI，继而引起Rpl36a等肿瘤基因表达失调，构成子代肿瘤发生的表观遗传及分子生物学基础。鉴于X连锁KDM6A“组蛋白去甲基酶”及“COMPASS复合物”功能在基因调控中的重要性，氧化应激是否通过KDM6A调控IVF胚胎XCI及肿瘤基因表达，促子代肿瘤发生，值得深入研究。而EGCG“抗氧化”、“抗甲基化”，能否恢复KDM6A表达，预防子代肿瘤？为此，构建KDM6A抑制或过表达体系，从表观遗传学角度探讨氧化应激下KDM6A调控胚胎XCI及肿瘤基因表达在子代肿瘤发生中的作用；胚胎体外培养体系添加EGCG行胚胎移植，明确EGCG是调节KDM6A、预防子代肿瘤的有效措施。为阐明人类IVF子代肿瘤发生机制奠定理论基础

In vitro fertilization (IVF) increased the risk of tumorigenesis in offspring, but the mechanism was unclear. We found that oxidative stress induced the aneuploidy of X chromosome in IVF embryos, suggesting that abnormal X chromosome inactivation (XCI) may occur. Pre-experiments confirmed that oxidative stress leads to abnormal XCI, which in turn causes the expression of Rpl36a and other "cancer genes" (tumor suppressors genes and oncogenes) to be dysregulated, which constitutes the epigenetic and molecular biological basis of tumorigenesis in offspring. In view of the importance of histone demethylase and compass complex function of X-linked KDM6A in gene regulation, whether oxidative stress regulates XCI and the expression of "cancer genes" in IVF embryos through KDM6A and promotes tumorigenesis in offspring is worthy of in-depth study. Furthermore, can EGCG improve KDM6A expression to prevent tumorigenesis in offspring via anti-oxidant and anti-methylation effects. Under oxidative stress, the effects of Kdm6a gene interference on regulation of XCI and cancer gene expression in embryos and then tumorigenesis in offspring will be observed, and the underlying epigenetic mechanisms will be investigated. In addition, we will add EGCG to embryo culture system in vitro and transfer embryos to identify whether EGCG is an effective strategy for preventing offspring tumorigenesis by regulating KDM6A. It will lay a theoretical foundation for elucidating the tumorigenesis mechanism of human IVF offspring.